How many Earths are there?

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In science fiction shows like Star Trek, the intrepid crew are always beaming down to earth-like planets. There they often discover grave danger - and occasionally find attractive aliens, keen on kissing Captain Kirk. Now new research from NASA's Kepler Space Telescope has revealed that Scotty might be in with a chance. The telescope has uncovered, NASA say, 17 billion earth-like planets - making scientists increasingly confident they might find some that are habitable. The new findings represent the latest update from the 600 million dollar mission launched by the U.S.A . in 2009. The Kepler Space Telescope is observing some 150,000 stars, just the faction of the galaxy. The survey suggests that every six star could have a planet similar in size to Earth. In the Milky Way alone this adds up to 17 billion planets. Nick Spole, the fellow from the Royal Astronomical Society says there’re a number of reasons that make these planets special. The temperature is not too cold, not too hot. And also the actual size of the planet – if it’s too small, it will lose its atmosphere over time and there won’t be the density of atmosphere, the right pressure that we’ve got on Earth. Dr. Simon Hodgkin from Cambridge Institute of Astronomy says so far the scientists don’t know much about other possible forms of lives. That’s why looking for planets similar to Earth is just a rule of thumb that the scientists use in their search for extraterrestrial creatures. Let’s look for planets that are a bit like ours. But we have no idea really what the range of environment the life could exist in and what form it might take. The Kepler Team also announced 461 new planet candidates revealed by the telescope. Ten of them could potentially host life. The Space Telescope detects the fractional change in the brightness of a star, when an object passes in front of it. If the change’s periodic, this could signal the presence of a planet orbiting the star. Scientists emphasize that  it’s important to understand that these are not confirmed plants and could be other celestial bodies. But Dr. Simon Hodgkin says he feels optimistic. Only a hundred so far of the Kepler candidates were confirmed to be planets. It’s quite likely that the majority of objects that Kepler is finding really are planets. What it means is that galaxy seems to be rich of planets, which is nice. It makes me feel reassured that we probably are not alone. Nick Spole says while the space telescopes of today are mostly used to collect statistics, the capacity of the new generation telescopes will exceed all our expectations. In the future there will be most sophisticated space telescopes that will be looking at the atmospheres of these planets. They will tell the exact make-up of the atmosphere. More hope now rests on the James Webb Space Telescope, a scientific successor to NASA’s Hubble. It works in the infra-red spectrum, allowing for unprecedented resolution and sensitivity. But it won’t launch until at least 2015. Astronomers hope it will not only find potentially habitable planets, but also to study the evolution of galaxies. Source: Voice of Russia